Sharp freezing container



Oct. 18, 1949. H. Y. JENNINGS SHARP FREEZING CONTAINER Filed Nov. 5, 1942 ENTQR. 22011295 ATTORNEYS Patented 18, 1949 UNITED STATES PATENT OFFICE SHARP FREEZING CONTAINER Harley Y. Jennings, Clio, Mich., assignor to Copeman Laboratories Company, Flint,

poration of Michigan Mich, a cor- Application November 5, 1942, Serial No. 464,641

This invention relates to slippable surfaces for ice tray partitions and the present application is a continuation-in-part of my prior application 2 Claims. ,(cii Isa-108.5)

Serial No. 334,293, filed May 9, 1940, which mal tion is the water-repellent and frictionless surface aforesaid.

The fact that the grid is made of a soft resilient material, such as rubber, enables it to take up the expansion produced by the changing of water to ice. This action compresses the rubber and of course causes some reduction in its crosssection during the freezing process. This is really an advantage as compared with a metal grid, because in the latter device the expanded ice binds the rigid walls of the grid firmly. However, even though the rubber grid made according to my invention may; be compressed as the ice freezes, there is no material stretching of the grid sections as it is removed from the ice for the reasons previously explained; that is, its low adhesion to the ice and its relatively frictionless surfaces.

Another improvement contemplated by the present invention is the provision of a rigid central bar in the grid to facilitate the removal thereof. When the bar is rigid one end may be pivoted on the edge of the tray to provide leverage. 7

Other objects and features of the invention having to do with detail of construction and with treatment of the grids will be further brought out in the following description and claims.

' In the drawings:

Fig. 1 is a perspective view of an ice tray containing a rubber grid.

Fig. 2 is a sectional view on lines 2-2 of Fig. 1 showing, in dotted lines, the grid being removed from the tray and its frozen contents by elevating one end thereof.

Fig. 3 is a section taken on line 3-3 of Fig. 1.

Fig. 4 is a bottom plan view of a portion ofa grid illustrating the tapered walls thereof;

Fig. 5 is an enlarged partial view of the pivot end of the removing bar of the grid.

Fig. 6 is a partial perspective view of a conventional rubber tray having surfaces produced according to my invention.

Referring to the drawings, iii denotes a metal tray capable of limited distortion as disclosed in the Geyer Patent No. 2,122,937. Although this type of tray is preferred I have found that any metal tray which can be twisted slightly will answer the purposes of my invention. Also preferably the interior surfaces of the tray should.

be untreated; or should be treated only slightly so that the ice cubes will always adhere to the walls of the tray when the grid is removed or slipped from the ice.

The grid H is preferably made of soft flexible rubber of high quality and comprisesthe usual longitudinal center strip [2 and a plurality of cross-pieces l3. It is desirable that the grid should extend a slight distance above the side walls of thetray so that the upper part of the grid shall not be enclosed by a layer of ice when the contents of the tray are frozen. Preferably the center [2 and the cross pieces l3 should taper, or in other words, be of gradually decreasing thickness from top to bottom to assist in the removal of the grid and it is also desirable that the cross pieces l3 should taper or be of gradually decreasing thickness from the center strip toward the side walls of the tray. The general contour of tlZe grid members is disclosed in detail in A relatively heavy reinforcing head It is molded along the top of the centerstrip I 2 and is sible and desirable to mold similar reinforcing beads IS on the top of each of the cross pieces l3. A handle or finger grip I1 is molded integrally with the grid at one end of the center piece to aflord a means for grasping the grid when it is being stripped from the tray and its frozen contents.

r The other end of the center reinforcement is shown in detail in Figs. 2 and 5. This end is provided with a fin-like depending portion I8 which forms a notch to receive the edge 20 of the end wall of tray ID. The end of the tray then serves as a fulcrum for the center bar It and greatly facilitates the removalof the grid. As shown by the dotted lines of Fig. 2, the grids l3 are pulled aside from, as well as up from, their recesses so that the removal is easy.

In order to provide the highly desirable slip" finish to the rubber grid, or in other words, a surface which is water-repellent and offers little frictional resistance to the ice when the grid is stripped therefrom, I have found that certain treatments may be applied to the rubber which greatly facilitate the removal of the grid from the .frozen mass, with a minimum of effort and withtutes or substances having rubber-like properties, as Neoprene and "'Ihiokol and wherever in the specifications and following claims the term rubber is used, it is intended to include not only rubber, natural or synthetic, but such rubber substitutes as are capable of reacting with the substances herein described or their equivalents, to produce similar results.

One process for practicing my invention comprises the immersion of a grid or tray in a solution of a compound of the sulphur group, which term I apply to compounds of sulphur. For example an excellent slippable surface is produced on a rubber grid by immersingit in a mixture of 80% concentrated sulphuric acid and 20% glycerol.

Obviously my invention is not limited to tapering rubber grids, or grids of any particular configuration, or even to grids themselves. Conventional rubber trays of varying sizes and shapes have been successfully treated according to the foregoing method and have shown an ease of ice removal far superior to similar untreated devices.

For example, very satisfactory ice removal has been obtained from a flexible rubber tray such as is shown at 20 in Fig. 4, in which the grid members 2| are molded integrally with the side and bottom walls of the tray.

Rubber trays and grids incorporating my improved surface have a characteristic velvety feel, and can be distinguished from the conventional untreated products by the relative ease with which they will slip over friction-resistant surfaces as compared with untreated trays and grids under the same conditions.

What I claim is:

1. As a new article of manufacture, a sharp freezing container for substances to be frozen, and partitions for dividing the container into a plurality of ice cube molds, said partitions being formed of resilient, easily distortable rubber, the surface of which is a reaction product of rubber treated by immersion in a liquid mixture of sulphuric acid and glycerol.

2. As a new article of manufacture, a sharp freezing container for substances to'be frozen, and partitions for dividing the container-into a plurality of ice cube molds, said partitions being formed of resilient, easily distortable rubber, the surface of which is a reaction product of rubber treated by immersion in a liquid mixture of r concentrated sulphuric acid and 20% glycerol.

HARLEY Y. JENNINGS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,102,456 Brill et a1 Dec. 14, 1937 2,303,938 Jennings Dec. 1, 1942 

